Integrated air conditioning module for a bus

ABSTRACT

An air conditioning module having all the necessary components for conditioning air, is so sized and arranged that when placed in an internal compartment of a bus, has its respective openings register with an existing return air duct and a supply air duct on the bus. The compartments and modules are so arranged that they can be paired in back-to-back relationship, with one on each side of a longitudinal center line of the bus. Each of the modules has an intermediate partition dividing the module into an upper evaporator section and a lower condensing section. A mixer flap is placed in an intermediate position with respect to the partition such that its position may be selectively adjusted to thereby vary the amount of fresh air and return air that is passed through the condenser coil and evaporator coil, respectively.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Ser. No. 10/429,583, filed May5, 2003, now allowed, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

This invention relates generally to air conditioning systems and, moreparticularly, to an air conditioning system which is integrated into theinternal structure of a bus.

The conventional integrated bus air conditioning systems contain acondenser mounted in a luggage compartment and an evaporator mounted inthe luggage compartment or in a separate compartment between thepassenger compartment floor and the luggage compartment underneath thefloor. The evaporator takes in the return air through a central returnair duct mounted under the floor of the passenger compartment and blowsthe conditioned supply air into a side wall supply air duct. Thecondenser, which, is interconnected to the evaporator by a refrigeranttube, operates to condense the refrigerant in the circuit by way of theoutside air that is brought in from and eventually discharged to theambient air.

As part of the refrigeration circuit which is fluidly interconnected bytubing to both the evaporator and the condenser, an open drivereciprocating compressor is generally directly driven by a belt drivefrom the bus engine, such that the speed of the compressor is dependenton the speed of the drive engine. Accordingly, when the bus is at idlespeed, for example, the capacity of the air conditioning system issubstantially reduced. Further, the refrigeration connections betweenthe compressor and the air conditioning system is generally expensive toinstall, difficult to service, and somewhat unreliable because ofpossible refrigeration leaks and the need to maintain a compressor shaftseal.

Also typical of such a bus air conditioning system is the use ofexisting DC power to power the evaporator and condenser blower motors.Because of relatively low brush life for such motors, reliability andexpense can also be a problem.

It is therefore an object of the present invention to provide animproved integrated air conditioning system for a bus.

Another object of the present invention is the provision for anintegrated air conditioning system that does not occupy a significantportion of a luggage compartment on a bus.

Yet another object of the present invention is the provision in a busfor an air conditioning system whose performance is not significantlyaffected by the engine speed of a bus.

Yet another object of the present invention is an integrated bus airconditioning system which is economical to install and reliable in use.

Yet another object of the present invention is an integrated bus airconditioning system that is accessible and easy to service.

Still another object of the present invention is an integrated airconditioning system for a bus which is economical to manufacture andeffective in use.

These objects and other features and advantages become more readilyapparent upon reference to the following descriptions when taken inconjunction with the appended drawings.

SUMMARY OF THE INVENTION

Briefly, in accordance with one aspect of the invention, a plurality ofmodules are placed under the floor of a passenger compartment of a bus,with each module having a complete air conditioning system which can becontrolled independently of the speed of the engine.

By yet another aspect of the invention, each module has aninvertor/controller which is interconnected to receive power for agenerator and provide controlled AC power to the drive motors of acompressor and the condenser and evaporator blowers.

By yet another aspect of the invention, a plurality of compact modulesare slidably installed into or near a luggage compartment of a bus so asto facilitate easy access for servicing the units.

In accordance with another aspect of the invention, the modules are sodesigned that, when installed in their positions on the bus, theirsupply air outlet opening and return air inlet openings register withthe existing supply air duct and return air duct on the bus.

In the drawings as hereinafter described, a preferred embodiment isdepicted; however various other modifications and alternateconstructions can be made thereto without departing from the true spritand scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the modules of the present invention asinstalled in a bus.

FIG. 2 is a perspective view of a module in accordance with the presentinvention.

FIG. 3 is a cutaway perspective view thereof.

FIG. 4 is a schematic illustration of the electrical power connectionson the module.

FIG. 5 shows the air flow connections between the module and theexisting ducts on the bus.

FIG. 6 is an expanded view of a portion thereof.

FIG. 7 a-7 c show cutaway perspective views of the modules with the airflow patterns for different positions of the mixing flap.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1, the inventive modules are shown at 11 asinstalled in a typical passenger bus having an existing side wall ductsystem 12 and an existing return air duct 13, both extendinglongitudinally on the bus. The side wall duct system is located withinthe side walls and communicates with the passenger compartment by way ofa plurality of openings. The return air duct 13 is located along thelongitudinal center line of the bus, near or just under the flooring orseats, and fluidly communicates with the passenger compartment by way ofa number of openings.

As will be seen, the modules 14 are located below the floor of thepassenger compartment and above the luggage compartments 16 and arepreferably slidably installed to allow for easy access to accommodateservicing. They are relatively shallow in height and therefore occupy arelatively small space. They are paired, in back-to-back relationship,with the longitudinal position thereof being adjustable to meet theneeds of the individual bus application. The manner in which theyinterface with the existing side wall ducts 12 and the return air duct13 will be described hereinafter.

The construction and components of the module 14 can be seen in FIGS. 2and 3 wherein a housing 17 includes a lower wall 18, an upper wall 19,an inner end wall 21 and an outer end wall 22. An intermediate partition23 divides the internal space between a condenser section 24 in thelower portion of the housing and an evaporator section 26 in an upperportion thereof. Within the condenser section 24 is a condenser coil 27and a condenser fan 28. The condenser fan 28 is of the draw-thru typewhich functions to draw outdoor air into a condenser air intake opening31, pass through the condenser 27 and flow out of the housing by way ofa condenser fan discharge opening 32 to the atmosphere.

Within the evaporator section 26 there is disposed an evaporator coil 33and a evaporator fan 34 driven by an evaporator fan motor 36. Theevaporator fan 34 is also the draw-thru type which acts to draw air intothe evaporator air intake opening 37, through the evaporator 33 and outa supply air outlet opening 38. Both the condenser fan 28 and theevaporator fan 34 are of the transverse type as shown and preferablyhave forward swept blades.

Near the longitudinal mid point of the module, the intermediatepartition 23 is made discontinuous and a fresh/return/exhaust air flap39 is hindgely mounted therein so as to selectively mix the variousflows of air as described hereinabove such that portions of those airstreams are diverted to other flow streams within the module as will bemore fully described hereinafter.

Also disposed within the housing 17 is a refrigeration circuit as shownin FIG. 4 to include a compressor 41 driven by an electric motor 45 andwith its discharge being fluidly connected to the condenser 27, which inturn is fluidly connected to an expansion valve 40 which discharges tothe evaporator 33, which in turn is fluidly connected to the compressorintake to complete the circuit. This closed circular refrigerationsystem operates in a conventional manner to circulate refrigerant which,by the various changes of state, provides for cooling of air at theevaporator 33 and the condensing of the refrigerant as it passes throughthe condenser coil 27. An inverter 42 is also provided within the modulefor the purpose of providing power to the various components within themodule.

The providing of power to the module occurs by way of the circuitry asshown in FIG. 4 wherein the bus motor or engine 43 drives a generator 44which in turn feeds electrical power to the inverter/controller 42.Controlled power is then provided by the inverter/controller 42 to theindividual motors 29, 45 and 36 as shown, with the controller respondingto control sensors 46 to discreetly control the speed of the respectivemotors. Each of the modules mounted in the bus have a similar invertorand control apparatus that is fed by the generator to provide AC powerto its various drive motors.

Referring now to FIGS. 5 and 6, there is shown the manner in which theindividual modules are mounted within the bus so as to interface withthe existing side wall duct system 12 and return air duct system 13. Inessence, the individual modules are identical and are sized and soarranged that when inserted into the opening under the floor of the bus,the evaporator air intake opening 37 registers with an opening in theexisting return air duct 13, and the supply air outlet opening 38registers with the opening in the existing side wall duct system 12 asshown. In addition, the condenser air intake opening 31 is disposed nearthe outer side of the bus wherein fresh air can be taken in fromoutside.

In conventional integrated bus air conditioning systems, wherein thecondenser is located in a luggage compartment, there is a passage fromthe luggage compartment for providing fluid communication from thecondenser discharge opening to the outside. Accordingly, there is noexisting condenser outlet duct that will suffice for use with thepresent modules. Thus, this component must be added as shown at 47 inFIGS. 5 and 6. Here, a single condenser air outlet duct 47 communicatesat its upper portion with each of the identical modules on either sideof the center line of the bus, and acts to conduct the flow of air fromthe condenser fan discharge opening 32 of each to a discharge opening 48at the lower end of the condenser air outlet duct 47 as shown.

Referring now to FIG. 7 a-7 c, the fresh air flap 39 is shown in variouspositions for selectively directing the flow of air within both thecondenser section 24 and evaporator section 26 and for mixing the flowswithin the two sections.

In FIG. 7 a, the fresh air flap is in a horizontal position such that itsimply forms a continuation of the intermediate partition 23. When inthis position, all of the return air passes through the evaporatorsection 26 and through the evaporator coil 33 to be discharged out thesupply air outlet duct 38. Similarly, all of the fresh air from theoutside passes into the condenser air intake opening 31, passes throughthe condenser coil 27, and is discharged from the condenser fandischarge opening 32.

In FIG. 7 b, the fresh air flap 39 is in an intermediate positionwherein a portion of the return air is diverted from the evaporatorsection 26 and passes downwardly to enter the stream of air passingthrough the condenser coil 27 and out the condenser fan dischargeopening 32. At the same time, a portion of the fresh air is divertedfrom the condenser section 24 to pass upwardly into the evaporatorsection 26, through the evaporator coil 33 and out the supply air outletopening 38. In this way a portion of the return air is dischargedoutside and is replenished with fresh air from outside which is thencooled and then supplied to the supply air ducts.

In FIG. 7 c, the fresh air flap 39 is placed in the vertical positionwherein it completely blocks the flow of air flowing through both thecondenser section 24 and evaporator section 26. When in this positionall of the return air entering the evaporator air intake opening 37passes through the condenser coil 27 and is discharged out the condenserfan discharge opening 32, and all of the fresh air passes from thecondenser section 24 to the evaporator section 26, through theevaporator coil 33 and out the supply outlet air opening 38.

It should, of course, be understood that the fresh air flap 39 can beplaced in any other intermediate position not shown in order to obtainthe desired mixtures that will meet the needs of the particular busapplication, while at the same time taking into account theenvironmental conditions outside.

While this invention has been described with reference to the particularstructure disclosed herein it should be understood that it is notconfined to the details set forth in this application, but is ratherintended to cover any modifications and changes as may come within thescope of the following claims:

1-17. (Cancelled)
 18. An air conditioning module for placement in aninternal compartment of a bus having a return air duct and a supply airduct fluidly communicating with said internal compartment, comprising: ahousing sized to fit into the internal compartment; a longitudinallyextending divider wall for dividing said housing into an evaporatorsection and a condenser section; an evaporator coil disposed in saidevaporator section and having an associated evaporator fan for causingair to flow through said evaporator coil and out a supply air outletopening of the module to the supply air duct; a condenser coil disposedin said condenser section and having an associated condenser fan forcausing air to flow through said condenser coil and out a condenserdischarge opening of the module; and a mixing flap disposed in themodule and being adjustable to vary an amount of return air flow passingfrom the return air duct into the evaporator section and through saidevaporator coil.
 19. An air conditioning module as set forth in claim 18wherein said mixing flap simultaneously adjusts the amount of return airflow that passes from the return air duct into the evaporator section,into said condenser section and through said condenser coil.
 20. An airconditioning module as set forth in claim 19 wherein the volume of saidreturn air flowing to said evaporator section and said condenser sectionare inversely proportional.
 21. An air conditioning module as set forthin claim 18 wherein said mixing flap also simultaneously adjustablyvaries an amount of fresh air that enters a condensate air intakeopening in the module, passes through said condenser section, passesthrough said condenser and out said condenser discharge opening.
 22. Anair conditioning module as set forth in claim 21 wherein said mixingvalve simultaneously adjusts the volume of fresh air that passes fromthe condenser section into the evaporator section, through theevaporator coil and to the supply air duct.
 23. An air conditioningmodule as set forth in claim 18 wherein said longitudinally extendingdivider divides said housing into an upper and a lower section.
 24. Anair conditioning module as set forth in claim 18 wherein said evaporatorfan is of the transverse type.
 25. An air conditioning module as setforth in claim 18 wherein said evaporator fan is located downstream ofsaid evaporator coil.
 26. An air conditioning module as set forth inclaim 18 wherein said internal compartment includes a condenser airoutlet duct and further wherein said condenser discharge opening fluidlycommunicates therewith.